This invention relates to gas guns, and, more particularly, to a pressure regulator assembly for controlling the velocity of projectiles fired by the gun.
Gas guns such as CO.sub.2 guns and air guns use pressurized gas to propel a projectile, for example, a BB or a pellet, from the gun. The pressurized gas is stored in a gas chamber in the gun, and when the gun is fired, a valve is opened to permit the pressurized gas to flow from the gas chamber to the barrel to propel the projectile.
The force which is exerted on the projectile can vary, for example, because of temperature variations, loss of pressure in the gas reservoir, or changes in the duration of valve opening. Variations in the force cause changes in the velocity of the projectile.
The invention provides a pressure regulating assembly which controls the velocity of the projectile by regulating the pressure within the gas chamber rather than by regulating the duration of valve opening. The regulator assembly includes a spring-biased piston which is slidable within a gas seal between the gas reservoir and the gas chamber. The piston permits pressurized gas to flow from the reservoir to the gas chamber until the pressure in the gas chamber which acts on the piston equalizes with the spring force on the piston. At that point the piston moves into sealing engagement with the gas seal. The regulator assembly will pressurize the gas chamber to the same pressure each time the gun is fired regardless of the temperature or pressure of the reservoir. The spring force on the piston can be varied as desired to adjust the pressure in the gas chamber and therefore the velocity of the projectile.